The present invention relates to an Arabic-Persian Alphabet input device and, more particularly, to an Arabic-Persian Alphabet input device that can easily input Arabic and Persian using a keyboard and be applied to cellular phones whose buttons (keys) are limited in number as various electronic appliances such as a personal computer trend toward miniaturization.
Arabic Alphabet is made up of 28 consonants and 8 vowels. The consonants are independently used, and the vowels change pronunciations of other characters. Except that there are four different characters, Persian Alphabet is substantially identical to the Arabic Alphabet.
Unlike Latin Alphabets, the Arabic-Persian Alphabet has characteristics as follows: (1) a morphological relationship between characters is relatively low; (2) each of the vowels is disposed over or under each of the consonants; (3) in any case, the vowels may be omitted; and (4) a consonant shape is varied depending on whether one consonant is consecutive to another consonant.
Therefore, it is very difficult to apply the Arabic-Persian Alphabet to electronic input devices such as keyboard whose buttons (keys) are limited in number.
With the remarkable advance in electric and electronic technologies, electronic appliances such as cell phones, personal digital assistant (PDA), pagers, game machines, remote controllers, cameras, and home electronics trend toward miniaturization and high-tech. Note that the cell phones include CDMA phones, PCS phones, TDMA phones, GSM phones, AMPS phones, and IMT-2000 phones. As functions of the electronic appliances are improved, there is an increasing requirement for expressing and inputting characteristics to the electronic appliances. Accordingly, what is needed is to develop methods (apparatus) for inputting the Arabic-Persian Alphabet to a cell phone whose buttons (keys) are limited in number.
In order to overcome the foregoing disadvantages, the present invention provides an Arabic-Persian Alphabet input apparatus based on a handwriting manner. Since the Arabic-Persian Alphabet input apparatus according to the invention automatically or manually determines the disposal of two or more consecutive characters, users need not remember the disposal of the characters.
The Arabic-Persian Alphabet input apparatus according to the invention includes an Alphabet input unit, an Alphabet database unit, an Alphabet extracting unit, a form database unit, and a combined form determining unit.
Without a specific mention, the xe2x80x9cArabicxe2x80x9d means not only Arabic but also Persian.
The Alphabet input unit is a kind of an input device such as keyboard, a keypad or a touch screen, and has a plurality of basic keys and one function key. Ten or more basic figures, which are extracted from analyzed Arabic Alphabet forms, are allocated to the basic keys. It will be understood that special function keys (e.g., a send key, a pause key, menu keys etc. in a cell phone) needed in electronic appliances may be added to the basic keys. Also an Arabic-Number-English shift key and special character input keys may be added thereto, if necessary.
As mentioned above, the pure Arabic Alphabet is made up of 28 consonants (hereinafter referred to as xe2x80x9cIndependent Alphabetxe2x80x9d including their varied characters) and 8 vowels (hereinafter referred to as xe2x80x9cVowel Alphabetxe2x80x9d), as shown in FIG. 1. In case of the Persian, the Independent Alphabet of four characters corresponding to the Arabic vowels is added.
The Vowel Alphabet has a small number of characters and simple forms, while the Independent Alphabet has a large number of characters and complicated forms. Therefore, the basic figures are preferably extracted from forms of the Independent Alphabet. A function key in the Alphabet input unit may be a space key or a shift key. The function key serves to indicate that inputting a series of Arabic words or a group of Arabic words is completed, and serves to shift a cursor of an input window by one point. When inputting characters   where no character follows, it is preferable that a function key input signal is automatically generated to shift the cursor by one point.
The Alphabet database unit stores information on each coded Arabic character so as to correspond to combinations of basic key input signals in the Alphabet input unit. When a basic key input signal is initially inputted from the Alphabet input unit or is inputted following a function key signal, the Alphabet extracting unit searches the Alphabet data base unit to extract an Arabic character corresponding to the combination of the inputted basic key signal. The Alphabet database unit is physically stored in a storage such as a random access memory (RAM) or a read-only memory (ROM). The Alphabet extracting unit may be a kind of a program. The Alphabet database unit and the Alphabet extracting unit may be physically monolithic database or database programs.
Except the characters , characters of the Independent Alphabet generally change in their forms when they are disposed at the beginning, middle, and ending of the words. Thus, the form database unit stores information on combined forms of consecutive characters. Since the Vowel Alphabet is located over or under the Independent Alphabet, the form database unit preferably stores the location information of the Vowel Alphabet.
In a case where a character extracted by the Alphabet extracting unit is consecutive to a previously extracted character, the combined form determining unit searches the form database unit to determine a combined form of the extracted two characters.
One or two variation keys may be added to the basic keys. Characters of the Vowel Alphabet, which are disposed over and under characters of the Independent Alphabet to change pronunciations thereof, are inscribed on the variation keys.
In a case where a variation key  is added, when a variation key input signal is inputted one, twice, three times, four times, five times, six times, and seven times, the Alphabet database unit additionally includes information that the inputted signals are regarded as the Vowel Alphabet based oh the displayed order thereof. And the form database unit additionally stores position information of characters that are disposed over or under the characters of the Arabic Alphabet to change their pronunciations.
In a case where two variation keys are added, characters disposed over characters of the Independent Alphabet are inscribed on a first variation key  and characters disposed thereunder are inscribed on a second variation key . In this case, the Alphabet database unit additionally includes information that when a first variation key input signal is inputted one, twice, three time, and four times, the inputted signals are regarded as , , , and , respectively. Further, the Alphabet database unit additionally includes information that when the second variation key input signal is inputted once and twice, the inputted signals are regarded as  and  respectively.
Although xe2x80x9cArabicxe2x80x9d or xe2x80x9cPersianxe2x80x9d are used in this specification, it will be understood that the input apparatus according to the invention may be applied to the Alphabets of languages having a similarity in forms to the xe2x80x9cArabicxe2x80x9d or xe2x80x9cPersianxe2x80x9d.
The embodiments of the present invention will now be described more fully hereinafter with reference to accompanying drawings. The embodiments and drawings are merely examples of the invention, and various modifications and alterations may be made without departing from the spirit an scope of the invention.